Brain Dump on Landmines

My Response Letter to my Friend's MySpace Bulletin

Ok, just to make you happy, I'll tell you everything I can think of about landmines. This is all from memory, stream of consciousness, and without looking anything up. :-)

Landmines come in two major types - anti-personnel, and anti-vehicle (or anti-tank).

Anti-personnel landmines are most commonly designed with small to moderate explosive charges and lots of fragmentation. In other words, they're similar to hand grenades, only more specialized. Typically, anti-per. landmines are triggered by pronged sensors sensitive to touch (i.e. you step on them). However, they can also be strung with tripwires, and I'm sure there are more complex varieties out there.

Three specific designs for anti-per. landmines that you may or may not have heard of:

"Bouncing Betty" - I forget the real name of these. They are about the size of a can of soup, maybe a little bigger. They have a basic pronged trigger on the top of the can. Typical installation is to hand bury the landmine so the top is flush with the soil. The trigger is then armed and you get the hell away from it. Once stepped on, there is a two-phase explosive charge. The first charge is a propellant charge that pops the can out of the hole and up to about chest height (say 4ft). The second charge is timed to coincide with the height of the jump, and detonates the can into a fragmentation barrage. I think they don't detonate until you let your foot off the trigger, but it would be foolish to rely on my memory in this matter. These were commonly used in Vietnam and other late 20th century conflicts, but I think they are out of favor due to the manual installation steps.

"Toe Poppers" - These are small landmines with small explosive charges. The design is aimed at blowing off just the foot or leg of a soldier. Horrendous, but also doubly effective from a military point of view. Injured soldiers tie up more resources (doctors, etc.) than dead soldiers, thus causing more grief for your opponent. I don't know much about the design specifics of toe poppers, but what is there to know. It's pretty straight forward.

"Claymores" - The Claymore is a US Army directional landmine. It is placed on stakes with one side facing the expected location of the enemy. It comes with a manual trigger system - aka "command detonation" - (on a long cord), or it can be detonated via tripwire. Deployed by the Army sometime in the 60s or 70s, I'm not sure if it's in use today or not.

I don't know any specific examples of anti-tank landmines, but I assume they would be based on the general principle of a shaped charge. Shaped charges use specially crafted explosive blocks to convert a piece of metal into a plasma jet. These plasma jets can penetrate significant amounts of armor, and typically ignite damn near everything they touch on the inside of the vehicle. As an added bonus, landmines typically strike the bottom of a vehicle, which is almost always the most lightly armored section.

Anti-vehicle/anti-tank landmines can be pressure or magnetic triggered. I'm not sure which is more common, or if additional triggering methods are common place yet. In either event, they generally pose little threat to infantry when vehicles are not present. The explosive charges in anti-tank landmines obviously tend to be much larger than anti-per. landmines. The last time I saw anti-tank landmines, they were about the size of a large dinner plate or a serving plate you might use for a turkey.

Landmines are typically deployed in only a few different manners. First, the slowest and most basic is the hand deployment. Not very "en vogue" these days. There are landmine laying vehicles which can plant or scatter landmines over an area while they drive. Finally, the most time-efficient deployment method is via air. Landmines can be deployed via airplane, rocket, or artillery shell. Obviously, air deployment is much less controlled than hand or vehicular deployment. So it is more commonly used in "area denial" deployments.

Area denial deployment seeks to prevent an enemy from moving through an area for strategic or tactical purposes. This is in contrast to the other major use of landmines - defensive works construction. Defensive works construction is more along the lines of the "DMZ" in Korea or some other border or installation defense situation.

So, specific examples, you might deploy landmines around a air field to help defend it from enemy attack. This would be defensive works construction. You might also seed landmines via rocket into a valley along a major highway and railroad line to prevent the enemy from moving his troops using that railroad and road. This would be an area denial use.

"Smart Mine" technologies have at least two components. The first smart mine research was aimed at designing landmines with better sensor/trigger systems. This included landmines with special radar or vibration sensors, and the ability to aim side-facing shaped charges, or to deploy airborne "bomblets" when a target was detected. There was lots and LOTS of crossover between this area and cluster bomb research.

The second area of research is making landmines which expire and become non-dangerous after a set time period. This is a direct result of the growing pressure from groups opposed to the harmful side-effects of widespread landmine use in "low intensity" conflicts.

This problem is of direct interest to you, because it is the whole reason people are training people, dogs, rats, and probably anything else with a nose to find and remove landmines. Once a landmine is deployed, it is active and dangerous indefinitely. In areas such as the Middle East and some parts of Africa, there are literally decades worth of old landmines scattered throughout the countryside. These old landmines maim and kill civilians constantly. The regimes responsible for deploying the landmines are commonly long gone, or if they still exist, they rarely care about the civilian impact. So Non Governmental Organizations (NGOs) formed to try and sponsor the removal of these landmine fields.

On top of the landmine problem, there is lots of detritus from war which continues to be dangerous. Many types of military ordinance may fail to detonate, and lay on the surface or semi-buried for years. (Dolly Sods Wilderness Area, east of Canaan Valley, is a former military artillery range from the 40s, and old unexploded ordinance is still found by hikers to this day.) To compound the problem, many explosive compounds used in military weapons are not stable after long periods of time. So these unexploded ordinances become more dangerous as their explosive loads become less stable. Although rarely reported, this is what led to the Army not searching some weapon dumps in Iraq - the ordinance was deemed too unstable to disturb for inspection. This is another area where landmines and cluster bombs cross over. Cluster bombs are notorious (and sometimes specifically designed) for not having all of the bomblets explode on impact. These left behind bomblets pose a serious hazard to anyone coming in contact with the target area.

So, how does a landmine get removed? The "best" way is probably through the use of a specialized mine-clearing vehicle. There is a vehicle, I think referred to as the "Flailer", that is used by the US Army. It has lots of heavy chains with weights on the ends mounted on a large rotor shaft. It also has LOTS of armor between the chains and the rest of the vehicle. When the chains are spinning at full speed, they literally shred any mine that doesn't explode when they hit it. This machine is very thorough and fast, but is also expensive and large. In combat situations, a similar flail device can be mounted on special purpose combat engineer tanks. Alternatively, long explosive "ropes" can be deployed across a minefield using rockets. These ropes are then detonated, destroying or displacing the mines in the immediate area, and clearing a safe lane for soldiers. Combat Engineers can also resort to the old-fashioned plow, but I suspect it is not nearly as effective as the flail techniques.

More practically, a lot of mine clearing is done by hand with metal detectors, trained animals, soil probes (i.e. sticks), and very very patient humans. I think there is a large emphasis on trained dogs (and rats, I guess) because they tend to be quicker than a human working with detectors. Human mine clearing teams are also much easier to deploy to restricted terrain - like an Afghan village in the middle of no-where.

The basic drill for clearing a minefield is establishing a border that completely contains the dangerous area. After this border is established, a team works from the border in across a lane. Probes can be pushed sideways into the dirt to try and locate landmines ahead of the team. Metal detectors and dogs trained to smell explosives are also useful. Once a landmine is found, it can be either detonated in place (typically via rifle, I suppose) or removed and defused. I know which technique I would prefer, but I don't know which is actually most commonly used. As the team moves forward, a stake-and-rope lane is marked out showing which area is safe. Repeat the process until the entire danger area is cleared.

Improvised Explosive Devices (IEDs), commonly used in Iraq, are large home-made landmines. My understanding is that typical IEDs are constructed out of artillery shells, but other large explosive charges could be used. These are almost exclusively the concern of military Explosive Ordinance Disposal (EOD) teams, not civilian NGO teams. Due to their improvised nature, IEDs can be much more dangerous to disarm. I suspect they are detonated in-situ whenever possible, but I don't have anything factual to back that up.

So, that's about all I can think of off-hand. Hope you enjoyed it. I think I'll post this on my blog too, just to see what people correct me on. :-)